Clocked half-rail differential logic with sense amplifier and shut-off

ABSTRACT

Clocked half-rail differential logic circuits with sense amplifier and shut-off are activated by a delayed clock and include a sense amplifier circuit that is triggered by a second delayed clock and a shut-off device. The addition of the sense amplifier circuit, and second delayed clock signal allows the sense amplifier circuit to act as the driver and therefore there is no need for increasing the size of the differential logic network to provide a driver function. The addition of the shut-off device provides a half-rail differential logic circuit with shut-off that does not experience the large or “dip” experienced by prior art half-rail differential logic circuits and is therefore more power efficient.

FIELD OF THE INVENTION

The present invention relates generally to logic circuits and, moreparticularly, to half-rail differential logic circuits.

BACKGROUND OF THE INVENTION

With the emergence of an electronics market that stresses portability,compact size, lightweight and the capability for prolonged remoteoperation, a demand has arisen for low power circuits and systems. Thisdemand has motivated circuit designers to depart from conventionalcircuit designs and venture into more power efficient alternatives. Aspart of this effort, half-rail differential logic has emerged as animportant design tool for increasing power efficiency.

FIG. 1 shows a schematic diagram of one embodiment of a clockedhalf-rail differential logic circuit 100 designed according to theprinciples of the invention set forth in patent application Ser. No.09/927,751, entitled “Clocked Half-Rail Differential Logic”, filed Aug.9, 2001, in the name of the present inventor, assigned to the assigneeof the present invention, and incorporated herein by reference, in itsentirety. As seen in FIG. 1, a clock signal CLK is coupled to an inputnode 132 of a clock inverter 134 to yield a clock-not signal CLKBAR atoutput node 136 of clock inverter 134.

As also seen in FIG. 1, clocked half-rail differential logic circuit 100includes a first supply voltage 102 coupled to a source, or first flowelectrode 130, of a PFET 101. The signal CLKBAR is coupled to a controlelectrode or gate 103 of first PFET 101 and a control electrode or gate129 of a first NFET 109. A drain, or second flow electrode 104, of firstPFET 101 is coupled to both a source, or first flow electrode 106, of asecond PFET 105 and a source, or first flow electrode 108, of a thirdPFET 107. A control electrode or gate 116 of second PFET 105 is coupledto a first flow electrode 140 of first NFET 109 and an OUTBAR terminal113. A control electrode or gate 114 of third PFET 107 is coupled to asecond flow electrode 138 of first NFET 109 and an OUT terminal 111. Adrain, or second flow electrode 110, of second PFET 105 is coupled toOUT terminal 111 and a drain, or second flow electrode 112, of thirdPFET 107 is coupled to OUTBAR terminal 113.

OUT terminal 111 is coupled to a first terminal 118 of a logic network123 and OUTBAR terminal 113 is coupled to a second terminal 120 of logicnetwork 123. Logic network 123 includes any type of differential logicand/or circuitry used in the art including various logic gates, logicdevices and circuits. Logic network 123 also includes first and secondIN terminals 151 and 153 that are typically coupled to an OUT and OUTBARterminal of a previous clocked half-rail differential logic circuit withsense amplifier and shut-off stage (not shown).

Logic network 123 also includes third terminal 122 coupled to a drain,or first flow electrode 124, of a second NFET 125. A gate or controlelectrode 127 of second NFET 125 is coupled to the signal CLK and asource, or second flow electrode 126, of second NFET 125 is coupled to asecond supply voltage 128.

A particular embodiment of a clocked half-rail differential logiccircuit 100 is shown in FIG. 1. Those of skill in the art will recognizethat clocked half-rail differential logic circuit 100 can be easilymodified. For example, different transistors, i.e., first, second andthird PFETs 101, 105 and 107 or first and second NFETs 109 and 125 canbe used. In particular, the NFETs and PFETS shown in FIG. 1 can bereadily exchanged for PFETs and NFETs by reversing the polarities of thesupply voltages 102 and 128, or by other well known circuitmodifications. Consequently, the clocked half-rail differential logiccircuit 100 that is shown in FIG. 1 is simply used for illustrativepurposes.

Clocked half-rail differential logic circuit 100 has two modes, orphases, of operation; a pre-charge phase and an evaluation phase. In oneembodiment of a clocked half-rail differential logic circuit 100, in thepre-charge phase, the signal CLK is low or a digital “0” and the signalCLKBAR is high or a digital “1”. Consequently, first PFET 101 and secondNFET 125 are not conducting or are “off” and logic network 123 isisolated from first supply voltage 102 and second supply voltage 128. Inaddition, during the pre-charge phase, first NFET 109 is conducting oris “on” and, therefore, OUT terminal 111 is shorted to OUTBAR terminal113. Consequently, the supply voltage to logic network 123 isapproximately half the supply voltage 102, i.e., for a first supplyvoltage 102 of Vdd and a second supply voltage 128 of ground, logicnetwork 123 operates at around Vdd/2. During pre-charge, second andthird PFETs 105 and 107 are typically not performing any function.

In one embodiment of a clocked half-rail differential logic circuit 100,in the evaluation phase, the signal CLK is high or a digital “1” and thesignal CLKBAR is low or a digital “0”. Consequently, first PFET 101 andsecond NFET 125 are conducting or are “on” and first NFET 109 is notconducting or is “off”. Consequently, depending on the particular logicin logic network 123, either second PFET 105, or third PFET 107, isconducting or is “on” and the other of second PFET 105, or third PFET107, is not conducting or is “off”. As a result, either OUT terminal 111goes from approximately half first supply voltage 102 to approximatelysecond supply voltage 128 or OUTBAR terminal 113 goes from approximatelyhalf first supply voltage 102 to approximately first supply voltage 102,i.e., for a first supply voltage 102 of Vdd and a second supply voltage128 of ground, OUT terminal 111 goes from approximately Vdd/2 to zeroand OUTBAR terminal 113 goes from approximately Vdd/2 to Vdd.

Clocked half-rail differential logic circuit 100 marked a significantimprovement over prior art half-rail logic circuits in part becauseclocked half-rail differential logic circuit 100 does not require thecomplex control circuit of prior art half-rail differential logiccircuits and is therefore simpler, saves space and is more reliable thanprior art half-rail differential logic circuits. As a result, clockedhalf-rail differential logic circuits 100 are better suited to thepresent electronics market that stresses portability, compact size,lightweight and the capability for prolonged remote operation. However,clocked half-rail differential logic circuit 100 has some limitations.

For instance, clocked half-rail differential logic circuit 100 workedvery well under conditions of a light load, for instance underconditions where fan out was less than four. However, clocked half-raildifferential logic circuit 100 was less useful under conditions of aheavy load, for instance, in cases where fan out exceeded four. Theshortcomings of clocked half-rail differential logic circuit 100 aroseprimarily because under heavy load conditions logic network 123, and thetransistors and components making up logic network 123, had to beincreased in size to act as a driver for the next stage in the cascade.This in turn meant that logic network 123 was large, slow andinefficient. The problem was further aggravated as additional clockedhalf-rail differential logic circuits 100 were cascaded together to formthe chains commonly used in the industry. Consequently, the fullpotential of clocked half-rail differential logic circuit 100 was notrealized and its use was narrowly limited to light load applications.

In addition during the evaluation phase, clocked half-rail differentiallogic circuit 100 drew excess power unnecessarily as the relevantinputs, 151 or 153, to logic network 123 were transitioning low to shutoff the path of one of the complementary OUT terminals, OUT terminal 111or OUTBAR terminal 113, to ground. The high OUT terminal, OUT terminal111 or OUTBAR terminal 113, therefore experienced a “dip” or pre-chargedhigh, during the transition when the inputs 151 or 153 switched fromhigh to low and a short circuit current, or crossbar current, path wasestablished from Vdd 102 to ground. This “dip” or pre-charged high wasundesirable and resulted in significant power being wasted.

In addition, the structure of clocked half-rail differential logiccircuit 100 was particularly susceptible to noise. This problem wasextremely undesirable, and damaging, since, as discussed above,typically, multiple clocked half-rail differential logic circuits 100were cascaded in long chains (not shown) of clocked half-raildifferential logic circuits 100. In these chain configurations, thesusceptibility of clocked half-rail differential logic circuit 100 tonoise meant that each successive stage of the chain contributedadditional noise and was even more adversely affected by the noise thanthe previous stage. Consequently, a few stages into a chain of clockedhalf-rail differential logic circuits 100 noise became the dominantfactor in the chain.

What is needed is a method and apparatus for creating half-raildifferential logic circuits that are capable of efficient use underheavy loads and are therefore more flexible, more space efficient andmore reliable than prior art half-rail differential logic circuits. Inaddition, a half-rail differential logic circuit is needed that does notexperience the large “dip” experienced by clocked half-rail differentiallogic circuit 100 and is therefore more power efficient. Finally, it isdesirable to have a half-rail differential logic circuit that is moreresistant to noise than clocked half-rail differential logic circuitwith sense amplifier and shut-off 100.

SUMMARY OF THE INVENTION

The clocked half-rail differential logic circuits with sense amplifierand shut-off of the invention include a sense amplifier circuit that istriggered by the delayed clock of the following stage, i.e., the clockinput to the sense amplifier circuit of the clocked half-raildifferential logic circuit with sense amplifier and shut-off of theinvention is additionally delayed with respect to the delayed clock thatdrives the clocked half-rail differential logic. The addition of thesense amplifier circuit, and second delayed clock signal, according tothe invention, allows the sense amplifier circuit to act as the driverand therefore there is no need for increasing the size of the logicnetwork, and the transistors and components making up the logic network,to provide the driver function. Consequently, the clocked half-raildifferential logic circuits with sense amplifier and shut-off of theinvention are capable of operating efficiently under heavy loadconditions without the increased size and the significant reduction inspeed associated with prior art half-rail differential logic circuits.In addition, the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention require less space, aresimpler, dissipate less heat and have fewer components to potentiallyfail.

In addition, according to the present invention, clocked half-raildifferential logic circuits with sense amplifier and shut-off includeshut-off devices to minimize the “dip” at the high output node that wasassociated with prior art clocked half-rail differential logic circuits.The shut-off device of the invention isolates the high OUT terminalimmediately from the IN terminals when the complementary OUT terminal ispulled to ground. Consequently, according to the present invention, thewindow period, or path, for the short circuit current, or crossbarcurrent, is significantly decreased and power is saved.

In addition, since clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention include a shut-off device,the high OUT terminal is isolated from the IN terminals and the noiseimmunity of the clocked half-rail differential logic circuits with senseamplifier and shut-off of the invention is significantly better thanprior art clocked half-rail differential logic circuits because noise onthe IN terminal does not affect the high OUT terminal after evaluation.Consequently, the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention are better suited forapplication in cascaded chains.

As discussed above, the clocked half-rail differential logic circuitswith sense amplifier and shut-off of the invention can be cascadedtogether to form the chains commonly used in the industry. When theclocked half-rail differential logic circuits with sense amplifier andshut-off of the invention are cascaded together, the advantages of theclocked half-rail differential logic circuits with sense amplifier andshut-off of the invention are particularly evident and the gains interms of noise immunity, power efficiency, size reduction andflexibility are further pronounced.

In particular, one embodiment of the invention is a cascaded chain ofclocked half-rail differential logic circuits with sense amplifier andshut-off. The chain includes a first clocked half-rail differentiallogic circuit with sense amplifier and shut-off. The first clockedhalf-rail differential logic circuit with sense amplifier and shut-offincludes: a first clocked half-rail differential logic circuit withsense amplifier and shut-off first clock in terminal; at least one firstclocked half-rail differential logic circuit with sense amplifier andshut-off data IN terminal; at least one first clocked half-raildifferential logic circuit with sense amplifier and shut-off data OUTterminal; and a first clocked half-rail differential logic circuit withsense amplifier and shut-off second clock in terminal.

The cascaded chain of the invention also includes a second clockedhalf-rail differential logic circuit with sense amplifier and shut-off.The second clocked half-rail differential logic circuit with senseamplifier and shut-off includes: a second clocked half-rail differentiallogic circuit with sense amplifier and shut-off first clock in terminal;at least one second clocked half-rail differential logic circuit withsense amplifier and shut-off data IN terminal; at least one secondclocked half-rail differential logic circuit with sense amplifier andshut-off data OUT terminal; and a second clocked half-rail differentiallogic circuit with sense amplifier and shut-off second clock interminal.

According to the invention, the at least one first clocked half-raildifferential logic circuit with sense amplifier and shut-off data OUTterminal is coupled to the at least one second clocked half-raildifferential logic circuit with sense amplifier and shut-off data INterminal to form the chain. According to the invention, a first clocksignal is coupled to the first clocked half-rail differential logiccircuit with sense amplifier and shut-off first clock in terminal and asecond clock signal is coupled to the first clocked half-raildifferential logic circuit with sense amplifier and shut-off secondclock in terminal and the second clocked half-rail differential logiccircuit with sense amplifier and shut-off first clock in terminal.According to the invention, the second clock signal is delayed withrespect to the first clock signal by a predetermined delay time.

In one embodiment of the invention, a delay circuit is coupled betweenthe first clocked half-rail differential logic circuit with senseamplifier and shut-off clock in terminal and the second clockedhalf-rail differential logic circuit with sense amplifier and shut-offfirst clock in terminal to provide the predetermined delay time. In oneembodiment of the invention, the delay circuit is also coupled betweenthe first clocked half-rail differential logic circuit with senseamplifier and shut-off clock in terminal and the first clocked half-raildifferential logic circuit with sense amplifier and shut-off secondclock in terminal to provide the predetermined delay time.

One embodiment of the invention is a clocked half-rail differentiallogic circuit with sense amplifier and shut-off that includes a clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal and a clocked half-rail differential logic circuit withsense amplifier and shut-off OUTBAR terminal.

The clocked half-rail differential logic circuit with sense amplifierand shut-off also includes a first transistor including a firsttransistor first flow electrode, a first transistor second flowelectrode and a first transistor control electrode. The first transistorfirst flow electrode is coupled to a first supply voltage.

The clocked half-rail differential logic circuit with sense amplifierand shut-off also includes a second transistor, the second transistorincluding a second transistor first flow electrode, a second transistorsecond flow electrode and a second transistor control electrode. Thefirst transistor second flow electrode is coupled to the secondtransistor first flow electrode and the second transistor second flowelectrode is coupled to the clocked half-rail differential logic circuitwith sense amplifier and shut-off OUT terminal.

The clocked half-rail differential logic circuit with sense amplifierand shut-off also includes a third transistor, the third transistorincluding a third transistor first flow electrode, a third transistorsecond flow electrode and a third transistor control electrode. Thefirst transistor second flow electrode is coupled to the thirdtransistor first flow electrode and the third transistor second flowelectrode is coupled to the clocked half-rail differential logic circuitwith sense amplifier and shut-off OUTBAR terminal.

The clocked half-rail differential logic circuit with sense amplifierand shut-off also includes a fourth transistor, the fourth transistorincluding a fourth transistor first flow electrode, a fourth transistorsecond flow electrode and a fourth transistor control electrode. Thesecond transistor control electrode is coupled to the fourth transistorfirst flow electrode and the clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal. The thirdtransistor control electrode is coupled to the fourth transistor secondflow electrode and the clocked half-rail differential logic circuit withsense amplifier and shut-off OUT terminal.

The clocked half-rail differential logic circuit with sense amplifierand shut-off also includes a logic network, the logic network includinga logic network first IN terminal, a logic network second IN terminal, alogic network OUT terminal, a logic network OUTBAR terminal and a logicnetwork fifth terminal.

The clocked half-rail differential logic circuit with sense amplifierand shut-off also includes a fifth transistor, the fifth transistorincluding a fifth transistor first flow electrode, a fifth transistorsecond flow electrode and a fifth transistor control electrode. Thefifth transistor first flow electrode is coupled to the logic networkfifth terminal and the fifth transistor second flow electrode is coupledto a second supply voltage.

A first clock signal CLKA is coupled to the fifth transistor controlelectrode of the fifth transistor of the clocked half-rail differentiallogic circuit with sense amplifier and shut-off. A first clock-notsignal CLKBAR is coupled to the first transistor control electrode ofthe first transistor of the clocked half-rail differential logic circuitwith sense amplifier and shut-off and the fourth transistor controlelectrode of the fourth transistor of the clocked half-rail differentiallogic circuit with sense amplifier and shut-off.

In one embodiment of the invention, the clocked half-rail differentiallogic circuit with sense amplifier and shut-off also includes a senseamplifier circuit coupled between the clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal and theclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal.

In one embodiment of the invention, the clocked half-rail differentiallogic circuit with sense amplifier and shut-off sense amplifier circuitincludes a sixth transistor, the sixth transistor including a sixthtransistor first flow electrode, a sixth transistor second flowelectrode and a sixth transistor control electrode. The secondtransistor second flow electrode is coupled to the sixth transistorfirst flow electrode. The sixth transistor second flow electrode iscoupled to a first node. The sixth transistor control electrode iscoupled to the fourth transistor second flow electrode and the clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal.

In one embodiment of the invention, the clocked half-rail differentiallogic circuit with sense amplifier and shut-off sense amplifier circuitalso includes a seventh transistor, the seventh transistor including aseventh transistor first flow electrode, a seventh transistor secondflow electrode and a seventh transistor control electrode. The thirdtransistor second flow electrode is coupled to the seventh transistorfirst flow electrode. The seventh transistor second flow electrode iscoupled to a first node. The seventh transistor control electrode iscoupled to the third transistor second flow electrode and the clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal.

In one embodiment of the invention, the clocked half-rail differentiallogic circuit with sense amplifier and shut-off sense amplifier circuitalso includes an eighth transistor, the eighth transistor including aneighth transistor first flow electrode, an eighth transistor second flowelectrode and an eighth transistor control electrode. The eighthtransistor first flow electrode is coupled to the first node and theeighth transistor second flow electrode is coupled to a second supplyvoltage. A second clock signal CLKB is coupled to the eighth transistorcontrol electrode of the clocked half-rail differential logic withcircuit sense amplifier circuit. In one embodiment of the invention, thesecond clock signal CLKB is delayed a predetermined time with respect tothe first clock signal CLKA.

In one embodiment of the invention, the clocked half-rail differentiallogic circuit with sense amplifier and shut-off also includes a shut-offdevice coupled between the clocked half-rail differential logic circuitwith sense amplifier and shut-off OUT terminal and the clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTBARterminal and the logic network OUT terminal and logic network OUTBARterminal.

In one embodiment of the invention, the clocked half-rail differentiallogic circuit with sense amplifier and shut-off shut-off device includesa ninth transistor, the ninth transistor including a ninth transistorfirst flow electrode, a ninth transistor second flow electrode and aninth transistor control electrode. The second transistor second flowelectrode is coupled to the ninth transistor first flow electrode. Theninth transistor second flow electrode is coupled to the logic networkOUT terminal. The ninth transistor control electrode is coupled to thefourth transistor first flow electrode and the clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTBARterminal.

In one embodiment of the invention, the clocked half-rail differentiallogic circuit with sense amplifier and shut-off shut-off device alsoincludes a tenth transistor, the tenth transistor including a tenthtransistor first flow electrode, a tenth transistor second flowelectrode and a tenth transistor control electrode. The third transistorsecond flow electrode is coupled to the tenth transistor first flowelectrode. The tenth transistor second flow electrode is coupled to thelogic network OUTBAR terminal. The tenth transistor control electrode iscoupled to the fourth transistor second flow electrode and the clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal.

As discussed in more detail below, the clocked half-rail differentiallogic circuits with sense amplifier and shut-off of the invention arecapable of efficient use under heavy loads and are therefore moreflexible, more space efficient and more reliable than prior arthalf-rail differential logic circuits. In addition, the presentinvention provides a half-rail differential logic circuit with shut-offthat does not experience the large “dip” experienced by prior arthalf-rail differential logic circuits and is therefore more powerefficient. In addition, the present invention provides a half-raildifferential logic circuit with shut-off that is more resistant to noisethan prior art half-rail differential logic circuits.

It is to be understood that both the foregoing general description andfollowing detailed description are intended only to exemplify andexplain the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in, and constitute apart of this specification, illustrate embodiments of the invention and,together with the description, serve to explain the advantages andprinciples of the invention. In the drawings:

FIG. 1 shows a schematic diagram of a clocked half-rail differentiallogic circuit;

FIG. 2 shows a schematic diagram of one embodiment of a clockedhalf-rail differential logic circuit with sense amplifier and shut-offdesigned according to the principles of the present invention;

FIG. 3 shows one embodiment of a cascaded chain of clocked half-raildifferential logic circuits with sense amplifier and shut-off accordingto the principles of the present invention; and

FIG. 4 is a one embodiment of a timing diagram for the cascaded chain ofclocked half-rail differential logic circuits with sense amplifier andshut-off of the invention shown in FIG. 3.

DETAILED DESCRIPTION

The invention will now be described in reference to the accompanyingdrawings. The same reference numbers may be used throughout the drawingsand the following description to refer to the same or like parts.

The clocked half-rail differential logic circuits with sense amplifierand shut-off (200 in FIG. 2) of the invention include a sense amplifiercircuit (280 in FIG. 2) that is triggered by the delayed clock of thefollowing stage, i.e., the clock input (327A, 327B, 327C and 327N inFIG. 3) to the sense amplifier circuit of the clocked half-raildifferential logic circuits with sense amplifier and shut-off of theinvention is additionally delayed with respect to the delayed clock (361371, 381 and 391 in FIG. 3) that drives the half-rail differentiallogic. The addition of the sense amplifier circuit, and second delayedclock signal, according to the invention, allows the sense amplifiercircuit to act as the driver and therefore there is no need forincreasing the size of the logic network (223 in FIG. 2) to provide thedriver function. Consequently, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention are capableof operating efficiently under heavy load conditions without theincreased size and the significant reduction in speed associated withprior art half-rail differential logic circuits (100 in FIG. 1).

In addition, according to the present invention, clocked half-raildifferential logic circuits with sense amplifier and shut-off includeshut-off devices (290A and 290B in FIG. 2) to minimize the “dip” at thehigh output node that was associated with prior art clocked half-raildifferential logic circuits. The shut-off device of the inventionisolates the high terminal (211 or 213 in FIG. 2) immediately from theIN terminals (251 and 253 in FIG. 3) when the complementary OUT terminalis pulled to ground. Consequently, according to the present invention,the window period, or path, for the short circuit current, or crossbarcurrent, is significantly decreased and power is saved.

In addition, since clocked half-rail differential logic circuits withsense amplifier and shut-off include a shut-off device, the high OUTterminal is isolated from the IN terminals and the noise immunity of theclocked half-rail differential logic circuits with sense amplifier andshut-off of the invention is significantly better than prior art clockedhalf-rail differential logic circuits because noise on the IN terminaldoes not affect the high OUT terminal after evaluation. Consequently,the clocked half-rail differential logic circuits with sense amplifierand shut-off of the invention are better suited for application incascaded chains (301 in FIG. 3).

As discussed above, the clocked half-rail differential logic circuitswith sense amplifier and shut-off of the invention can be cascadedtogether to form the chains (301 in FIG. 3) commonly used in theindustry. When the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention are cascaded together, theadvantages of the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention are particularly evidentand the gains in terms of noise immunity, power efficiency, sizereduction and flexibility are further pronounced.

FIG. 2 shows a schematic diagram of one embodiment of a clockedhalf-rail differential logic circuit with sense amplifier and shut-off200 designed according to the principles of the present invention. Asseen in FIG. 2, a clock signal CLKA is coupled to an input node 232 of aclock inverter 234 to yield a clock-not signal CLKBAR at output node 236of clock inverter 234.

As also seen in FIG. 2, clocked half-rail differential logic circuitwith sense amplifier and shut-off 200 includes a first supply voltage202 coupled to a source, or first flow electrode 230, of a PFET 201. Thesignal CLKBBAR is coupled to a control electrode or gate 203 of PFET 201and a control electrode or gate 229 of a NFET 209. A drain, or secondflow electrode 204, of PFET 201 is coupled to both a source, or firstflow electrode 206, of a PFET 205 and a source, or first flow electrode208, of a PFET 207. A control electrode or gate 216 of PFET 205 iscoupled to a first flow electrode 240 of NFET 209 and an OUTBAR terminal213. A control electrode or gate 214 of PFET 207 is coupled to a secondflow electrode 238 of NFET 209 and an OUT terminal 211. A drain, orsecond flow electrode 210, of PFET 205 is coupled to OUT terminal 211and a drain, or second flow electrode 212, of PFET 207 is coupled toOUTBAR terminal 213.

Clocked half-rail differential logic circuit with sense amplifier andshut-off 200 includes a logic network 223. Logic network 223 includesany type of differential logic and/or circuitry used in the artincluding various logic gates, logic devices and circuits. Logic network223 includes first and second IN terminals 251 and 253 that aretypically coupled to an OUT and OUTBAR terminal of a previous clockedhalf-rail differential logic circuit with sense amplifier and shut-offstage (not shown) and logic network OUT terminal 218 and OUTBAR terminal220.

Logic network 223 also includes third terminal 222 coupled to a drain,or first flow electrode 224, of a NFET 225. A gate or control electrode227 of NFET 225 is coupled to the signal CLKA and a source, or secondflow electrode 226, of NFET 225 is coupled to a second supply voltage271.

According to the invention, clocked half-rail differential logic circuitwith sense amplifier and shut-off 200 also includes sense amplifiercircuit 280. In one embodiment of the invention, sense amplifier circuit280 includes a sixth transistor, NFET 215, including a drain 251, asource 253 and a control electrode or gate 252. Drain 210 of PFET 205 iscoupled to drain 251 of NFET 215. Source 253 of NFET 215 is coupled to afirst node 255. Gate 252 of NFET 215 is coupled to source 240 of NFET209 and clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal 213.

In one embodiment of the invention, sense amplifier circuit 280 alsoincludes a seventh transistor, NFET 217, including a drain 259, a source257 and a control electrode or gate 258. Drain 212 of PFET 207 iscoupled to drain 259 of NFET 217. Source 257 of NFET 217 is coupled tofirst node 255. Gate 258 of NFET 217 is coupled to drain 238 of NFET 209and clocked half-rail differential logic circuit with sense amplifierand shut-off OUT terminal 211.

In one embodiment of the invention, sense amplifier circuit 280 ofclocked half-rail differential logic circuit with sense amplifier andshut-off 200 also includes an eighth transistor, NFET 270, including adrain 218, a source 221 and a control electrode or gate 277. Drain 218of NFET 270 is coupled to first node 255. Source 221 of NFET 270 iscoupled to second supply voltage 271. A delayed, or second, clock signalCLKB is coupled to control electrode or gate 277 of NFET 270. Accordingto one embodiment of the invention, clock signal CLKB is delayed withrespect to clock signal CLKA by a predetermined time.

According to the invention, clocked half-rail differential logic circuitwith sense amplifier and shut-off 200 also includes shut-off device290A/290B. In one embodiment of the invention, shut-off device 290A/290Bincludes a ninth transistor, NFET 281 including a drain 283, a source285 and a control electrode or gate 287. Drain 210 of PFET 205 iscoupled to drain 283 of NFET 281. Source 285 of NFET 281 is coupled toOUT terminal 218 of logic network 223. Gate 287 of NFET 281 is coupledto source 240 of NFET 209 and clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal 213.

In one embodiment of the invention, shut-off device 290A/290B alsoincludes a tenth transistor, NFET 291 including a drain 293, a source295 and a control electrode or gate 297. Drain 212 of PFET 207 iscoupled to drain 293 of NFET 291. Source 295 of NFET 291 is coupled toOUTBAR terminal 220 of logic network 223. Gate 297 of NFET 291 iscoupled to drain 238 of NFET 209 and clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal 211.

A particular embodiment of a clocked half-rail differential logiccircuit with sense amplifier and shut-off 200 is shown in FIG. 2. Thoseof skill in the art will recognize that clocked half-rail differentiallogic circuit with sense amplifier and shut-off 200 can be easilymodified. For example, different transistors, i.e., PFETs 201, 205 and207 or NFETs 209, 215, 217, 225, 270, 281 and 291 can be used. Inparticular, the NFETs and PFETS shown in FIG. 2 can be readily exchangedfor PFETs and NFETs by reversing the polarities of the supply voltages202 and 271, or by other well known circuit modifications. Consequently,the clocked half-rail differential logic circuit with sense amplifierand shut-off 200 that is shown in FIG. 2 is simply used for illustrativepurposes.

As discussed above, clocked half-rail differential logic circuit withsense amplifier and shut-off 200 of the invention includes senseamplifier circuit 280 that is triggered by delayed, or second, clocksignal CLKB of the following stage, i.e., the clock signal CLKB to gate277 of NFET 270 of sense amplifier circuit 280 is additionally delayedwith respect to the first clock signal CLKA. As also noted above, Clocksignal CLKA is coupled to control electrode 277 of NFET 270. Clock-notsignal CLKABAR is coupled to gate 203 of PFET 201 and gate 229 of NFET209. The addition of sense amplifier circuit 280 and second delayedclock signal CLKB, according to the invention, allows sense amplifiercircuit 280 to act as the driver circuit and therefore there is no needfor increasing the size of the logic network 223, or the components oflogic network 223, to provide the driver function. Consequently, clockedhalf-rail differential logic circuit with sense amplifier and shut-off200 of the invention is capable of operating efficiently under heavyload conditions without the significant reduction in speed associatedwith half-rail differential logic circuits 100. In addition, clockedhalf-rail differential logic circuit with sense amplifier and shut-off200 requires less space, is simpler, dissipates less heat and has fewercomponents to potentially fail.

The addition of shut-off device 290A/290B, according to the presentinvention, allows clocked half-rail differential logic circuit withsense amplifier and shut-off 200 to minimize the “dip” at the highterminal 211 or 213 that was associated with prior art clocked half-raildifferential logic circuits (100 in FIG. 1). In operation, during thepre-charge phase, i.e., when signal CLKA is low, PFETs 205 and 207 areoff and shut-off device NFETs 281 and 291 are on, or conduct.

During evaluation, i.e., when signal CLKA is high, one of clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal 211 or clocked half-rail differential logic circuit withsense amplifier and shut-off OUTBAR terminal 213 is discharged throughlogic network 223 and the other one of clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal 213 orclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal 211 is pulled up, after experiencing a slight dipcaused by the IN terminals 251 and/or 253 continuing to transition low.Whichever one of the shut-off device NFETs 281 and 291 is controlled bythe low terminal, i.e., either clocked half-rail differential logiccircuit with sense amplifier and shut-off OUT terminal 211 or clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal 213, will then turn off and isolate the complementaryhigh terminal, i.e., clocked half-rail differential logic circuit withsense amplifier and shut-off OUTBAR terminal 213 or clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal 211. Whichever one of either clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal 211 orclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal 213 is low, that low terminal will also causeone of either PFET 205 or 207 to turn on or conduct. Consequently, thecross-coupled connection of PFETs 205 and 207 provides a latch-likefunction to maintain the voltage level after evaluation.

In short, shut-off device 290A/290B of the invention isolates the highOUT terminal (211 or 213) immediately from the IN terminals (251 and253) when the complementary OUT terminal (213 or 211) is pulled toground. Consequently, according to the present invention, the windowperiod, or path, for the short circuit current, or crossbar current, issignificantly decreased and power is saved.

In addition, since clocked half-rail differential logic circuits withsense amplifier and shut-off 200 include shut-off device 290A/290B, thehigh OUT terminal (211 or 213) is isolated from IN terminals (251 and253) and the noise immunity of clocked half-rail differential logiccircuits with sense amplifier and shut-off 200 of the invention issignificantly better than prior art clocked half-rail differential logiccircuits because noise on the IN terminals (251 and 253) does not affectthe high OUT terminal (211 or 213) after evaluation. Consequently,clocked half-rail differential logic circuits with sense amplifier andshut-off 200 of the invention are better suited for application incascaded chains.

As discussed above, clocked half-rail differential logic circuit withsense amplifier and shut-off 200 can be cascaded together with otherclocked half-rail differential logic circuits with sense amplifier andshut-off 200 to form the chains commonly used in the industry. Whenclocked half-rail differential logic circuits with sense amplifier andshut-off 200 of the invention are cascaded together, the advantages ofclocked half-rail differential logic circuit with sense amplifier andshut-off 200 is particularly evident and the gains in terms ofefficiency, size reduction and flexibility are further pronounced.

When clocked half-rail differential logic circuit with sense amplifierand shut-off 200 of the invention are cascaded together, the first clocksignal CLKA is, according to the invention, timed to be at least thedelay of the previous clocked half-rail differential logic circuit withsense amplifier and shut-off 200 (not shown) to ensure each clockedhalf-rail differential logic circuit with sense amplifier and shut-off200 of the invention is switched or “fired” only after it has receivedan input from the previous clocked half-rail differential logic circuitwith sense amplifier and shut-off 200.

FIG. 3 shows one embodiment of a cascaded chain 301 of clocked half-raildifferential logic circuits with sense amplifier and shut-off 300A,300B, 300C and 300N of the present invention. Each clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N represents a stage in cascaded chain 301. In oneembodiment of the invention, each clocked half-rail differential logiccircuit with sense amplifier and shut-off 300A, 300B, 300C and 300N issimilar to clocked half-rail differential logic circuit with senseamplifier and shut-off 200 discussed above with respect to FIG. 2.

As seen in FIG. 3, clocked half-rail differential logic circuit withsense amplifier and shut-off 300A includes: a first clock in terminal326A; a second clock in terminal 327A; an OUT terminal 311A; and anOUTBAR terminal 313A.

Clocked half-rail differential logic circuit with sense amplifier andshut-off 300B includes: a first clock in terminal 326B; a second clockin terminal 327B; an IN terminal 351B, coupled to OUT terminal 311A ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300A; an INBAR terminal 353B, coupled to OUTBAR terminal 313Aof clocked half-rail differential logic circuit with sense amplifier andshut-off 300A; an OUT terminal 311B; and an OUTBAR terminal 313B.Likewise, clocked half-rail differential logic circuit with senseamplifier and shut-off 300C includes: a first clock in terminal 326C; asecond clock in terminal 327C; an IN terminal 351C, coupled to OUTterminal 311B of clocked half-rail differential logic circuit with senseamplifier and shut-off 300B; an INBAR terminal 353C, coupled to OUTBARterminal 313B of clocked half-rail differential logic circuit with senseamplifier and shut-off 300B; an OUT terminal 311C; and an OUTBARterminal 313C.

Clocked half-rail differential logic circuit with sense amplifier andshut-off 300N includes: a first clock in terminal 326N; a second clockin terminal 327N; an IN terminal 351N, coupled to an OUT terminal 311N−1(not shown) of a clocked half-rail differential logic circuit with senseamplifier and shut-off 300N−1 (not shown); an INBAR terminal 353N,coupled to an OUTBAR terminal 313N−1 (not shown) of a clocked half-raildifferential logic circuit with sense amplifier and shut-off 300N−1 (notshown); an OUT terminal 311N; and an OUTBAR terminal 313N.

According to the invention, any number of clocked half-rail differentiallogic circuits with sense amplifier and shut-off 300A, 300B, 300C and300N can be employed with cascaded chain 301. As also shown in FIG. 3,and discussed above, OUT terminal 311A of clocked half-rail differentiallogic circuit with sense amplifier and shut-off 300A couples signal OUTAto IN terminal 351B of clocked half-rail differential logic circuit withsense amplifier and shut-off 300B and OUTBAR terminal 313A of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300A couples signal OUTBARA to INBAR terminal 353B of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B.Likewise, OUT terminal 311B of clocked half-rail differential logiccircuit with sense amplifier and shut-off 300B couples signal OUTB to INterminal 351C of clocked half-rail differential logic circuit with senseamplifier and shut-off 300C and OUTBAR terminal 313B of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300B couples signal OUTBARB to INBAR terminal 353C of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300C. Inaddition, OUT terminal 311N of clocked half-rail differential logiccircuit with sense amplifier and shut-off 300N couples signal OUTN to anIN terminal 351N+1 (not shown) of a clocked half-rail differential logiccircuit with sense amplifier and shut-off 300N+1 (not shown) and OUTBARterminal 313N of clocked half-rail differential logic circuit with senseamplifier and shut-off 300N couples signal OUTBARN to an INBAR terminal353N+1 (not shown) of a clocked half-rail differential logic circuitwith sense amplifier and shut-off 300N+1 (not shown).

According to the invention, each clocked half-rail differential logiccircuit with sense amplifier and shut-off 300A, 300B, 300C and 300N ofcascaded chain 301 receives its own delayed first clock signal CLKA 361,CLKB 371, CLKC 381 and CLKN 391, respectively. According to theinvention clock signals CLKA 361, CLKB 371, CLKC 381 and CLKN 391 areprovided to clocked half-rail differential logic circuit with senseamplifier and shut-off 300A, 300B, 300C and 300N, respectively, byintroducing delay circuits 363, 373, 383 and 393 between successiveclocked half-rail differential logic circuits with sense amplifier andshut-off 300A, 300B, 300C and 300N. Consequently, delay circuit 363introduces a delay time between signal CLKA 361, coupled to first clockin terminal 326A of clocked half-rail differential logic circuit withsense amplifier and shut-off 300A, and signal CLKB 371, coupled to firstclock in terminal 326B of clocked half-rail differential logic circuitwith sense amplifier and shut-off 300B. Delay circuit 373 introduces adelay time between signal CLKB 371 and signal CLKC 381, coupled to firstclock in terminal 326C of clocked half-rail differential logic circuitwith sense amplifier and shut-off 300C. Two delay circuits 363 and 373introduce two delay times between signal CLKA 361 and signal CLKC 381.Likewise, a series of N−1 delay circuits, and N−1 delay times, existsbetween signal CLKA 361 and signal CLKN 391, coupled to first clock interminal 326N of clocked half-rail differential logic circuit with senseamplifier and shut-off 300N, and a further delay circuit 393 introducesa further delay time between CLKN 391 and CLK N+1 (not shown) coupled toa first clock in terminal 326N+1 (not shown) of a clocked half-raildifferential logic circuit with sense amplifier and shut-off 300N+1 (notshown).

Delay circuits 363, 373, 383 and 393 are any one of many delay circuitsknown in the art such as inverters, or groups of inverters, gates,transistors or any other elements that introduce a time delay. Accordingto the invention, delay circuits 363, 373, 383 and 393 are used toensure the activation of each stage, i.e., each clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N, is timed such that the delay of the clock is longer thanthe evaluation duration of the previous stage. In one embodiment of theinvention, the delayed clock signals CLKA 361, CLKB 371, CLKC 381 andCLKN 391 are timed to switch high (active) when the differential inputvoltage to clocked half-rail differential logic circuit with senseamplifier and shut-off 300A, 300B, 300C and 300N reaches a predeterminedvoltage level. The clock delay can be adjusted according to thepredetermined differential voltage level required for robustness and thespecific needs of the circuit designer. This differential voltage levelis typically a function of process and will vary from circuit to circuitand system to system.

In addition, according to the invention, each clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N of cascaded chain 301 receives a second delayed clocksignal at its second clock in terminal 327A, 327B, 327C and 327N,respectively. In one embodiment of the invention, the second delayedclock signal for a given clocked half-rail differential logic circuitwith sense amplifier and shut-off 300A, 300B, 300C and 300N of cascadedchain 301 is the delayed clock signal of the following clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N in cascaded chain 301. In this embodiment of theinvention, the second delayed clock signal for a given clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N of cascaded chain 301 is provided by coupling the secondclock terminal 327A, 327B, 327C and 327N of a given clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, 300B,300C and 300N, respectively, to the first clock in terminal 326B, 326C,326D (not shown), 326N and 326N+1 (not shown) of the following stage300B, 300C, 300N and 300N+1 (not shown).

Thus, in FIG. 3, line 320A couples second clock in terminal 327A ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300A to first clock in terminal 326B of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B anddelay circuit 363 introduces a delay time between signal CLKA 361,coupled to first clock in terminal 326A of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A, andsignal CLKB 371, coupled to second clock in terminal 327A of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300A. Likewise, line 320B couples second clock in terminal 327B ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300B to first clock in terminal 326C of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300C anddelay circuit 373 introduces a delay time between signal CLKB 371,coupled to first clock in terminal 326B of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B, andsignal CLKC 381, coupled to second clock in terminal 327B of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300B.

Similarly, line 320C couples second clock in terminal 327C of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300C to first clock in terminal 326D (not shown) of a clocked half-raildifferential logic circuit with sense amplifier and shut-off 300D (notshown) and delay circuit 383 introduces a delay time between signal CLKC381, coupled to first clock in terminal 326C of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300C, andsignal CLKD 382, coupled to second clock in terminal 327C of clockedhalf-rail differential logic circuit with sense amplifier and shut-off300C. Likewise, line 320N couples first clock in terminal 326N+1 (notshown) of a clocked half-rail differential logic circuit with senseamplifier and shut-off 300N+1 (not shown) to second clock in terminal327N of clocked half-rail differential logic circuit with senseamplifier and shut-off 300N and delay circuit 393 introduces a delaytime between signal CLKN 391, coupled to first clock in terminal 326N ofclocked half-rail differential logic circuit with sense amplifier andshut-off 300N, and signal CLKN+1 392, coupled to second clock interminal 327N of clocked half-rail differential logic circuit with senseamplifier and shut-off 300N.

In one embodiment of the invention, second clock in terminals 327A,327B, 327C and 327N of clocked half-rail differential logic circuit withsense amplifier and shut-off 300A, 300B, 300C and 300N, respectively,are coupled to sense amplifiers (not shown in FIG. 3) in clockedhalf-rail differential logic circuit with sense amplifier and shut-off300A, 300B, 300C and 300N, such as sense amplifier circuit 280 in FIG.2, and the signals CLKB, CLKC, CLKD, and CLKN+1 are used as describedabove with respect to FIG. 2 to trigger the sense amplifiers (not shownin FIG. 3) in clocked half-rail differential logic circuit with senseamplifier and shut-off 300A, 300B, 300C and 300N.

FIG. 4 is one embodiment of a timing diagram for cascaded chain 301 ofclocked half-rail differential logic circuits with sense amplifier andshut-off 300A, 300B, 300C and 300N of FIG. 3. As seen in FIG. 3 and FIG.4 together, according to one embodiment of the invention, at time T0,i.e., point T0 400A in FIG. 4, signal CLKA 461 starts to go high. Aftera short switching delay 460, such as the short switching delay inherentin any circuit, signal OUTA 411A at OUTA terminal 311A starts to switchhigh at point 466. Corresponding signal OUTBARA at OUTBAR terminal 313Astarts to discharge to low at point 467. Note that, as discussed above,points 466 and 467 typically represent potentials of approximatelyVdd/2.

According to the present invention, signal CLKB 471 is delayed a delaytime 472 with respect to signal CLKA 461 by delay circuit 363. At point473, i.e., time T1 400B, signal CLKB 471 starts to rise and therebyactivates a sense amplifier, such as sense amplifier 280 in FIG. 2,which, according to the invention, is part of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300A. Oncethe sense amplifier is activated, output OUTA 411A pulls strongly tohigh starting at point 465 and reaches high point 464 rapidly. Note thedifference in the slope of signal OUTA between points 466 and 465, whenthe sense amplifier is not activated, and points 465 and 464, when thesense amplifier is activated. Likewise, corresponding signal OUTBARA413A pulls strongly low, starting at point 468, to low point 469 whenthe sense amplifier is activated.

At point 463A, in its pre-charge phase, CLKA 461 starts to switch low.After a short delay, OUTA 411A and OUTBARA 413A begin to equalize atpoints 464A and 469A, respectively, and reach approximate equilibrium atpoints 466A and 467A at a potential close to Vdd/2.

As also seen in FIG. 3 and FIG. 4 together, according to one embodimentof the invention, at time T1, i.e., point T1 400B in FIG. 4, signal CLKB471 starts to go high. After a short switching delay 470, such as theshort switching delay inherent in any circuit, signal OUTB 411B at OUTBterminal 311B starts to switch high at point 476. Corresponding signalOUTBARB at OUTBAR terminal 313B starts to discharge to low at point 477.Note that, as discussed above, points 476 and 477 typically representpotentials of approximately Vdd/2.

According to the present invention, signal CLKC 481 is delayed a delaytime 482 with respect to signal CLKB 471 by delay circuit 373. At point483, i.e., time T2 400C, signal CLKC 481 starts to rise and therebyactivates a sense amplifier, such as sense amplifier 280 in FIG. 2,which, according to the invention, is part of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300B. Oncethe sense amplifier is activated, output OUTB 411B pulls strongly tohigh starting at point 475 and reaches high point 474 rapidly. Note thedifference in the slope of signal OUTB between points 476 and 475, whenthe sense amplifier is not activated, and points 475 and 474, when thesense amplifier is activated. Likewise, corresponding signal OUTBARB413B pulls strongly low, starting at point 478, to low point 479 whenthe sense amplifier is activated.

At point 473A, in its pre-charge phase, CLKB 471 starts to switch low.After a short delay, OUTB 411B and OUTBARB 413B begin to equalize atpoints 474A and 479A, respectively, and reach approximate equilibrium atpoints 476A and 477A at a potential close to Vdd/2.

As also seen in FIG. 3 and FIG. 4 together, according to one embodimentof the invention, at time T2, i.e., point T2 400 c in FIG. 4, signalCLKC 481 starts to go high. After a short switching delay 480, such asthe short switching delay inherent in any circuit, signal OUTC 411C atOUTC terminal 311C starts to switch high at point 486. Correspondingsignal OUTBARC at OUTBAR terminal 313C starts to discharge to low atpoint 487. Note that, as discussed above, points 486 and 487 typicallyrepresent potentials of approximately Vdd/2.

According to the present invention, signal CLKD 491 is delayed a delaytime 492 with respect to signal CLKC 481 by delay circuit 383. At point493, i.e., time T3 400D, signal CLKD 491 starts to rise and therebyactivates a sense amplifier, such as sense amplifier 280 in FIG. 2,which, according to the invention, is part of clocked half-raildifferential logic circuit with sense amplifier and shut-off 300C. Oncethe sense amplifier is activated, output OUTC 411C pulls strongly tohigh starting at point 485 and reaches high point 484 rapidly. Note thedifference in the slope of signal OUTC between points 486 and 485, whenthe sense amplifier is not activated, and points 485 and 484, when thesense amplifier is activated. Likewise, corresponding signal OUTBARC413C pulls strongly low, starting at point 488, to low point 489 whenthe sense amplifier is activated.

At point 483A, in its pre-charge phase, CLKC 481 starts to switch low.After a short delay, OUTC 411C and OUTBARC 413C begin to equalize atpoints 484A and 489A, respectively, and reach approximate equilibrium atpoints 486A and 487A at a potential close to Vdd/2.

As discussed above, according to the invention, any number of clockedhalf-rail differential logic circuits with sense amplifier and shut-off300A, 300B, 300C and 300N can be employed with cascaded chain 301. Inaddition, the process discussed above will repeat for each switching ofthe system clock. Those of skill in the art will further recognize thatthe choice of signal highs and signal lows was made arbitrarily in FIG.4 for illustrative purposes only and that at other times, and in otherembodiments of the invention, signal highs could be replaced with signallows and vice-versa.

As discussed above, clocked half-rail differential logic circuit withsense amplifier and shut-off 200, 300A, 300B, 300C and 300N of theinvention include sense amplifier circuit 280 that is triggered by thedelayed clock of the following stage, i.e., the clock input to the senseamplifier circuit of the clocked half-rail differential logic circuitwith sense amplifier and shut-off of the invention is additionallydelayed with respect to the delayed clock that drives the half-raildifferential logic. The addition of the sense amplifier circuit, andsecond delayed clock signal, according to the invention, allows thesense amplifier circuit to act as the driver and therefore there is noneed for increasing the size of the logic network, or the transistorsand components making up the logic network, to provide the driverfunction. Consequently, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention are capableof operating efficiently under heavy load conditions without theincreased size and the significant reduction in speed associated withprior art half-rail differential logic circuits. In addition, theclocked half-rail differential logic circuits with sense amplifier andshut-off of the invention require less space, are simpler, dissipateless heat and have fewer components to potentially fail.

In addition, according to the present invention, clocked half-raildifferential logic circuit with sense amplifier and shut-off includeshut-off devices to minimize the “dip” at the high output node that wasassociated with prior art clocked half-rail differential logic circuits.The shut-off device of the invention isolates the high output terminalimmediately from the IN terminals when the complementary OUT terminal ispulled to ground. Consequently, according to the present invention, thewindow period, or path, for the short circuit current, or crossbarcurrent, is significantly decreased and power is saved.

In addition, since the clocked half-rail differential logic circuitswith sense amplifier and shut-off of the invention include a shut-offdevice, the high OUT terminal is isolated from the IN terminals and thenoise immunity of the clocked half-rail differential logic circuits withsense amplifier and shut-off of the invention is significantly betterthan prior art clocked half-rail differential logic circuits becausenoise on the IN terminal does not affect the high OUT terminal afterevaluation. Consequently, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention are bettersuited for application in cascaded chains.

As also discussed above, the clocked half-rail differential logiccircuits with sense amplifier and shut-off of the invention can becascaded together to form the chains commonly used in the industry. Whenthe clocked half-rail differential logic circuits with sense amplifierand shut-off of the invention are cascaded together, the advantages ofthe clocked half-rail differential logic circuit with sense amplifierand shut-off of the invention are particularly evident and the gains interms of efficiency, size reduction and flexibility are furtherpronounced.

The foregoing description of an implementation of the invention has beenpresented for purposes of illustration and description only, andtherefore is not exhaustive and does not limit the invention to theprecise form disclosed. Modifications and variations are possible inlight of the above teachings or may be acquired from practicing theinvention.

For example, for illustrative purposes specific embodiments of theinvention were shown with specific transistors. However, the NFETs andPFETS shown in the figures can be readily exchanged for PFETs and NFETsby reversing the polarities of the supply voltages or by other wellknown circuit modifications.

Consequently, the scope of the invention is defined by the claims andtheir equivalents.

What is claimed is:
 1. A cascaded chain of clocked half-raildifferential logic circuits with sense amplifier and shut-offcomprising: a first clocked half-rail differential logic circuit withsense amplifier and shut-off, said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off comprising: a firstclocked half-rail differential logic circuit with sense amplifier andshut-off first clock in terminal; a first clocked half-rail differentiallogic circuit with sense amplifier and shut-off second clock interminal; at least one first clocked half-rail differential logiccircuit with sense amplifier and shut-off data in terminal; and at leastone first clocked half-rail differential logic circuit with senseamplifier and shut-off data out terminal; a second clocked half-raildifferential logic circuit with sense amplifier and shut-off, saidsecond clocked half-rail differential logic circuit with sense amplifierand shut-off comprising: a second clocked half-rail differential logiccircuit with sense amplifier and shut-off first clock in terminal; asecond clocked half-rail differential logic circuit with sense amplifierand shut-off second clock in terminal; at least one second clockedhalf-rail differential logic circuit with sense amplifier and shut-offdata in terminal; and at least one second clocked half-rail differentiallogic circuit with sense amplifier and shut-off data out terminal; afirst clock signal coupled to said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off first clock in terminal;a second clock signal coupled to said second clocked half-raildifferential logic circuit with sense amplifier and shut-off first clockin terminal and said first clocked half-rail differential logic circuitwith sense amplifier and shut-off second clock in terminal, wherein;said at least one first clocked half-rail differential logic circuitwith sense amplifier and shut-off data out terminal is coupled to saidat least one second clocked half-rail differential logic circuit withsense amplifier and shut-off data in terminal, further wherein; saidsecond clock signal is delayed with respect to said first clock signalby a predetermined delay time.
 2. The cascaded chain of clockedhalf-rail differential logic circuits with sense amplifier and shut-offof claim 1, further comprising: a delay circuit coupled between saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off clock in terminal and said second clocked half-raildifferential logic circuit with sense amplifier and shut-off clock interminal for delaying said second clock signal with respect to saidfirst clock signal by said predetermined delay time.
 3. The cascadedchain of clocked half-rail differential logic circuits with senseamplifier and shut-off of claim 2, wherein; said delay circuit comprisesat least one inverter.
 4. The cascaded chain of clocked half-raildifferential logic circuits with sense amplifier and shut-off of claim2, wherein; said first clocked half-rail differential logic circuit withsense amplifier and shut-off comprises a sense amplifier circuit coupledto said first clocked half-rail differential logic circuit with senseamplifier and shut-off second clock in terminal; and said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offcomprises a sense amplifier circuit coupled to said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offsecond clock in terminal.
 5. A cascaded chain of clocked half-raildifferential logic circuits with sense amplifier and shut-offcomprising: a first supply voltage; a second supply voltage; a firstclocked half-rail differential logic circuit with sense amplifier andshut-off, said first clocked half-rail differential logic circuit withsense amplifier and shut-off comprising: a first clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal; a first clocked half-rail differential logic circuit withsense amplifier and shut-off OUTBAR terminal; a first transistor, saidfirst transistor comprising a first transistor first flow electrode, afirst transistor second flow electrode and a first transistor controlelectrode, said first supply voltage being coupled to said firsttransistor first flow electrode; a second transistor, said secondtransistor comprising a second transistor first flow electrode, a secondtransistor second flow electrode and a second transistor controlelectrode, said first transistor second flow electrode being coupled tosaid second transistor first flow electrode, said second transistorsecond flow electrode being coupled to said first clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal; a third transistor, said third transistor comprising a thirdtransistor first flow electrode, a third transistor second flowelectrode and a third transistor control electrode, said firsttransistor second flow electrode being coupled to said third transistorfirst flow electrode, said third transistor second flow electrode beingcoupled to said first clocked half-rail differential logic circuit withsense amplifier and shut-off OUTBAR terminal; a fourth transistor, saidfourth transistor comprising a fourth transistor first flow electrode, afourth transistor second flow electrode and a fourth transistor controlelectrode, said second transistor control electrode being coupled tosaid fourth transistor first flow electrode and said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal, said third transistor control electrode being coupledto said fourth transistor second flow electrode and said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal; a logic network, said logic network comprising a logicnetwork first IN terminal, a logic network second IN terminal, a logicnetwork OUT terminal, a logic network OUTBAR terminal and a logicnetwork fifth terminal; a fifth transistor, said fifth transistorcomprising a fifth transistor first flow electrode, a fifth transistorsecond flow electrode and a fifth transistor control electrode, saidfifth transistor first flow electrode being coupled to said logicnetwork fifth terminal, said fifth transistor second flow electrodebeing coupled to said second supply voltage; a first clocked half-raildifferential logic circuit with sense amplifier and shut-off senseamplifier circuit coupled between said first clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal and said first clocked half-rail differential logic circuitwith sense amplifier and shut-off OUTBAR terminal, said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit having an IN terminal coupled to a second clocksignal; a first clocked half-rail differential logic circuit with senseamplifier and shut-off shut-off device coupled between said firstclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal and said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal, saidlogic network OUT terminal being coupled to said first clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice and said logic network OUTBAR terminal being coupled to saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off shut-off device; a second clocked half-rail differentiallogic circuit with sense amplifier and shut-off, said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offcomprising: a second clocked half-rail differential logic circuit withsense amplifier and shut-off OUT terminal; a second clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTBARterminal; a first transistor, said first transistor comprising a firsttransistor first flow electrode, a first transistor second flowelectrode and a first transistor control electrode, said first supplyvoltage being coupled to said first transistor first flow electrode; asecond transistor, said second transistor comprising a second transistorfirst flow electrode, a second transistor second flow electrode and asecond transistor control electrode, said first transistor second flowelectrode being coupled to said second transistor first flow electrode,said second transistor second flow electrode being coupled to said firstclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal; a third transistor, said third transistorcomprising a third transistor first flow electrode, a third transistorsecond flow electrode and a third transistor control electrode, saidfirst transistor second flow electrode being coupled to said thirdtransistor first flow electrode, said third transistor second flowelectrode being coupled to said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal; afourth transistor, said fourth transistor comprising a fourth transistorfirst flow electrode, a fourth transistor second flow electrode and afourth transistor control electrode, said second transistor controlelectrode being coupled to said fourth transistor first flow electrodeand said first clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal, said third transistor controlelectrode being coupled to said fourth transistor second flow electrodeand said first clocked half-rail differential logic circuit with senseamplifier and shut-off OUT terminal; a logic network, said logic networkcomprising a logic network first IN terminal, a logic network second INterminal, a logic network OUT terminal, a logic network OUTBAR terminaland a logic network fifth terminal; a fifth transistor, said fifthtransistor comprising a fifth transistor first flow electrode, a fifthtransistor second flow electrode and a fifth transistor controlelectrode, said fifth transistor first flow electrode being coupled tosaid logic network fifth terminal, said fifth transistor second flowelectrode being coupled to said second supply voltage; a second clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit coupled between said second clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal and said second clocked half-rail differential logic circuitwith sense amplifier and shut-off OUTBAR terminal, said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit having an IN terminal coupled to a third clocksignal, a second clocked half-rail differential logic circuit with senseamplifier and shut-off shut-off device coupled between said secondclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal and said second clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUTBAR terminal, saidlogic network OUT terminal being coupled to said first clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice and said logic network OUTBAR terminal being coupled to saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off shut-off device, wherein; said second clock signal isdelayed with respect to said first clock signal by a predetermined delaytime and said third clock signal is delayed with respect to said secondclock signal by a predetermined delay time.
 6. The cascaded chain ofclocked half-rail differential logic circuits with sense amplifier andshut-off of claim 5, wherein; said first clocked half-rail differentiallogic circuit with sense amplifier and shut-off sense amplifier circuitcomprises: a sixth transistor, said sixth transistor comprising a sixthtransistor first flow electrode, a sixth transistor second flowelectrode and a sixth transistor control electrode, said secondtransistor second flow electrode being coupled to said sixth transistorfirst flow electrode, said sixth transistor second flow electrode beingcoupled to a first clocked half-rail differential logic circuit withsense amplifier and shut-off first node, said sixth transistor controlelectrode being coupled to said fourth transistor first flow electrodeand said first clocked half-rail differential logic circuit with senseamplifier and shut-off OUTBAR terminal; a seventh transistor, saidseventh transistor comprising a seventh transistor first flow electrode,a seventh transistor second flow electrode and a seventh transistorcontrol electrode, said third transistor second flow electrode beingcoupled to said seventh transistor first flow electrode, said seventhtransistor second flow electrode being coupled to said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offfirst node, said seventh transistor control electrode being coupled tosaid fourth transistor second flow electrode and said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal; an eighth transistor, said eighth transistor comprising aneighth transistor first flow electrode, an eighth transistor second flowelectrode and an eighth transistor control electrode, said eighthtransistor first flow electrode being coupled to said first clockedhalf-rail differential logic circuit with sense amplifier and shut-offfirst node, said eighth transistor second flow electrode being coupledto said second supply voltage, said eighth transistor control electrodebeing coupled to receive said second clock signal, further wherein; saida second clocked half-rail differential logic circuit with senseamplifier and shut-off sense amplifier circuit comprises: a sixthtransistor, said sixth transistor comprising a sixth transistor firstflow electrode, a sixth transistor second flow electrode and a sixthtransistor control electrode, said second transistor second flowelectrode being coupled to said sixth transistor first flow electrode,said sixth transistor second flow electrode being coupled to a secondclocked half-rail differential logic circuit with sense amplifier andshut-off first node, said sixth transistor control electrode beingcoupled to said fourth transistor first flow electrode and said secondclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal; a seventh transistor, said seventh transistorcomprising a seventh transistor first flow electrode, a seventhtransistor second flow electrode and a seventh transistor controlelectrode, said third transistor second flow electrode being coupled tosaid seventh transistor first flow electrode, said seventh transistorsecond flow electrode being coupled to said second clocked half-raildifferential logic circuit with sense amplifier and shut-off first node,said seventh transistor control electrode being coupled to said fourthtransistor second flow electrode and said second clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTterminal; an eighth transistor, said eighth transistor comprising aneighth transistor first flow electrode, an eighth transistor second flowelectrode and an eighth transistor control electrode, said eighthtransistor first flow electrode being coupled to said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offfirst node, said eighth transistor second flow electrode being coupledto said second supply voltage, said eighth transistor control electrodebeing coupled to receive said third clock signal.
 7. The cascaded chainof clocked half-rail differential logic circuits with sense amplifierand shut-off of claim 5, wherein; said first clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice comprises: a ninth transistor, said ninth transistor comprising aninth transistor first flow electrode, a ninth transistor second flowelectrode and a ninth transistor control electrode, said secondtransistor second flow electrode being coupled to said ninth transistorfirst flow electrode, said ninth transistor second flow electrode beingcoupled to said OUT terminal of said logic network, said ninthtransistor control electrode being coupled to said fourth transistorfirst flow electrode and said first clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal; a tenthtransistor, said tenth transistor comprising a tenth transistor firstflow electrode, a tenth transistor second flow electrode and a tenthtransistor control electrode, said third transistor second flowelectrode being coupled to said tenth transistor first flow electrode,said tenth transistor second flow electrode being coupled to said OUTBARterminal of said logic network, said tenth transistor control electrodebeing coupled to said fourth transistor second flow electrode and saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off OUT terminal, further wherein; said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offshut-off device comprises: a ninth transistor, said ninth transistorcomprising a ninth transistor first flow electrode, a ninth transistorsecond flow electrode and a ninth transistor control electrode, saidsecond transistor second flow electrode being coupled to said ninthtransistor first flow electrode, said ninth transistor second flowelectrode being coupled to said OUT terminal of said logic network, saidninth transistor control electrode being coupled to said fourthtransistor first flow electrode and said second clocked half-raildifferential logic circuit with sense amplifier and shut-off OUTBARterminal; a tenth transistor, said tenth transistor comprising a tenthtransistor first flow electrode, a tenth transistor second flowelectrode and a tenth transistor control electrode, said thirdtransistor second flow electrode being coupled to said tenth transistorfirst flow electrode, said tenth transistor second flow electrode beingcoupled to said OUTBAR terminal of said logic network, said tenthtransistor control electrode being coupled to said fourth transistorsecond flow electrode and said second clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal.
 8. Thecascaded chain of clocked half-rail differential logic circuits withsense amplifier and shut-off of claim 5, wherein; said logic network ofsaid first clocked half-rail differential logic circuit with senseamplifier and shut-off and said logic network of said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offcomprise differential logic.
 9. The cascaded chain of clocked half-raildifferential logic circuits with sense amplifier and shut-off of claim5, wherein; said logic network of said first clocked half-raildifferential logic circuit with sense amplifier and shut-off and saidlogic network of said second clocked half-rail differential logiccircuit with sense amplifier and shut-off comprise differential logicgates.
 10. The cascaded chain of clocked half-rail differential logiccircuits with sense amplifier and shut-off of claim 5, wherein; saidlogic network of said first clocked half-rail differential logic circuitwith sense amplifier and shut-off and said logic network of said secondclocked half-rail differential logic circuit with sense amplifier andshut-off comprise NMOS pass transistor logic; said logic network of saidfirst clocked half-rail differential logic circuit with sense amplifierand shut-off comprises at least one control variable input and at leastone pass variable input; and said logic network of said second clockedhalf-rail differential logic circuit with sense amplifier and shut-offcomprises at least one control variable input and at least one passvariable input.
 11. The cascaded chain of clocked half-rail differentiallogic circuits with sense amplifier and shut-off of claim 5, wherein;said first supply voltage is Vdd and said second supply voltage isground.
 12. The cascaded chain of clocked half-rail differential logiccircuits with sense amplifier and shut-off of claim 11, wherein; saidfirst transistor, said second transistor, and said third transistor ofsaid first clocked half-rail differential logic circuit with senseamplifier and shut-off and said first transistor, said secondtransistor, and said third transistor of said second clocked half-raildifferential logic circuit with sense amplifier and shut-off are PFETs.13. The cascaded chain of clocked half-rail differential logic circuitwith sense amplifier and shut-off of claim 12, wherein; said fourthtransistor, said fifth transistor, said sixth transistor, said seventhtransistor, said eighth transistor, said ninth transistor and said tenthtransistor of said first clocked half-rail differential logic circuitwith sense amplifier and shut-off and said fourth transistor, said fifthtransistor, said sixth transistor, said seventh transistor, said eighthtransistor, said ninth transistor and said tenth transistor of saidsecond clocked half-rail differential logic circuit with sense amplifierand shut-off are NFETs.
 14. A clocked half-rail differential logiccircuit with sense amplifier and shut-off comprising: a first supplyvoltage; a second supply voltage; a clocked half-rail differential logiccircuit with sense amplifier and shut-off OUT terminal; a clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal; a first transistor, said first transistor comprising afirst transistor first flow electrode, a first transistor second flowelectrode and a first transistor control electrode, said first supplyvoltage being coupled to said first transistor first flow electrode; asecond transistor, said second transistor comprising a second transistorfirst flow electrode, a second transistor second flow electrode and asecond transistor control electrode, said first transistor second flowelectrode being coupled to said second transistor first flow electrode,said second transistor second flow electrode being coupled to saidclocked half-rail differential logic circuit with sense amplifier andshut-off OUT terminal; a third transistor, said third transistorcomprising a third transistor first flow electrode, a third transistorsecond flow electrode and a third transistor control electrode, saidfirst transistor second flow electrode being coupled to said thirdtransistor first flow electrode, said third transistor second flowelectrode being coupled to said clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal; a fourthtransistor, said fourth transistor comprising a fourth transistor firstflow electrode, a fourth transistor second flow electrode and a fourthtransistor control electrode, said second transistor control electrodebeing coupled to said fourth transistor first flow electrode and saidclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal, said third transistor control electrode beingcoupled to said fourth transistor second flow electrode and said clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal; a logic network, said logic network comprising a logicnetwork first IN terminal, a logic network second IN terminal, a logicnetwork OUT terminal, a logic network OUTBAR terminal and a logicnetwork fifth terminal; a fifth transistor, said fifth transistorcomprising a fifth transistor first flow electrode, a fifth transistorsecond flow electrode and a fifth transistor control electrode, saidfifth transistor first flow electrode being coupled to said logicnetwork fifth terminal, said fifth transistor second flow electrodebeing coupled to said second supply voltage; a clocked half-raildifferential logic circuit with sense amplifier and shut-off senseamplifier circuit coupled between said clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal and saidclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal, said clocked half-rail differential logiccircuit with sense amplifier and shut-off sense amplifier circuit havingan IN terminal coupled to a second clock signal; a clocked half-raildifferential logic circuit with sense amplifier and shut-off shut-offdevice coupled between said clocked half-rail differential logic circuitwith sense amplifier and shut-off OUT terminal and said clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUTBAR terminal, said logic network OUT terminal being coupled to saidclocked half-rail differential logic circuit with sense amplifier andshut-off shut-off device and said logic network OUTBAR terminal beingcoupled to said clocked half-rail differential logic circuit with senseamplifier and shut-off shut-off device, wherein; said second clocksignal is delayed with respect to said first clock signal by apredetermined time.
 15. The clocked half-rail differential logic circuitwith sense amplifier and shut-off of claim 14, wherein; said clockedhalf-rail differential logic circuit with sense amplifier and shut-offsense amplifier circuit comprises: a sixth transistor, said sixthtransistor comprising a sixth transistor first flow electrode, a sixthtransistor second flow electrode and a sixth transistor controlelectrode, said second transistor second flow electrode being coupled tosaid sixth transistor first flow electrode, said sixth transistor secondflow electrode being coupled to a clocked half-rail differential logiccircuit with sense amplifier and shut-off first node, said sixthtransistor control electrode being coupled to said fourth transistorfirst flow electrode and said clocked half-rail differential logiccircuit with sense amplifier and shut-off OUTBAR terminal; a seventhtransistor, said seventh transistor comprising a seventh transistorfirst flow electrode, a seventh transistor second flow electrode and aseventh transistor control electrode, said third transistor second flowelectrode being coupled to said seventh transistor first flow electrode,said seventh transistor second flow electrode being coupled to saidclocked half-rail differential logic circuit with sense amplifier andshut-off first node, said seventh transistor control electrode beingcoupled to said fourth transistor second flow electrode and said clockedhalf-rail differential logic circuit with sense amplifier and shut-offOUT terminal; an eighth transistor, said eighth transistor comprising aneighth transistor first flow electrode, an eighth transistor second flowelectrode and an eighth transistor control electrode, said eighthtransistor first flow electrode being coupled to said clocked half-raildifferential logic circuit with sense amplifier and shut-off first node,said eighth transistor second flow electrode being coupled to saidsecond supply voltage, said eighth transistor control electrode beingcoupled to receive said second clock signal.
 16. The clocked half-raildifferential logic circuit with sense amplifier and shut-off of claim14, wherein; said first clocked half-rail differential logic circuitwith sense amplifier and shut-off shut-off device comprises: a ninthtransistor, said ninth transistor comprising a ninth transistor firstflow electrode, a ninth transistor second flow electrode and a ninthtransistor control electrode, said second transistor second flowelectrode being coupled to said ninth transistor first flow electrode,said ninth transistor second flow electrode being coupled to said OUTterminal of said logic network, said ninth transistor control electrodebeing coupled to said fourth transistor first flow electrode and saidclocked half-rail differential logic circuit with sense amplifier andshut-off OUTBAR terminal; a tenth transistor, said tenth transistorcomprising a tenth transistor first flow electrode, a tenth transistorsecond flow electrode and a tenth transistor control electrode, saidthird transistor second flow electrode being coupled to said tenthtransistor first flow electrode, said tenth transistor second flowelectrode being coupled to said OUTBAR terminal of said logic network,said tenth transistor control electrode being coupled to said fourthtransistor second flow electrode and said clocked half-rail differentiallogic circuit with sense amplifier and shut-off OUT terminal.
 17. Theclocked half-rail differential logic circuit with sense amplifier andshut-off of claim 14, wherein; said logic network of said clockedhalf-rail differential logic circuit with sense amplifier and shut-offcomprises differential logic.
 18. The clocked half-rail differentiallogic circuit with sense amplifier and shut-off of claim 14, wherein;said logic network of said clocked half-rail differential logic circuitwith sense amplifier and shut-off comprises differential logic gates.19. The clocked half-rail differential logic circuit with senseamplifier and shut-off of claim 14, wherein; said logic network of saidclocked half-rail differential logic circuit with sense amplifier andshut-off comprises NMOS pass transistor logic; and said logic network ofsaid clocked half-rail differential logic circuit with sense amplifierand shut-off includes at least one control variable input and at leastone pass variable input.
 20. The clocked half-rail differential logiccircuit with sense amplifier and shut-off of claim 14, wherein; saidfirst supply voltage is Vdd and said second supply voltage is ground.21. The clocked half-rail differential logic circuit with senseamplifier and shut-off of claim 18, wherein; said first transistor, saidsecond transistor, and said third transistor are PFETs.
 22. The clockedhalf-rail differential logic circuit with sense amplifier and shut-offof claim 19, wherein; said fourth transistor, said fifth transistor,said sixth transistor, said seventh transistor, said eighth transistor,said ninth transistor and said tenth transistor are NFETs.